With negative numbers, how do we know when the negative sign indicates that it is a subtraction or it is a negative number?

This is a question from Khan Academy:
(−5+7×1)−9×5
If you calculate the equation in the parentheses which equals 2, then the equation becomes 2-9x5. At this point, would you calculate the 9x5 part as 9 x 5 then subtract 2 or -9 x 5 then add 2. I know that this isn't the greatest example since it would equal -43 regardless but there are some equations where it would change the entire equation.

The p-value of the given hypothesis is; 0.9999

The formula for the z-score of proportions is;

z = (p^ - p)/√(p(1 - p)/n)

where;

p^ is sample proportion

p is population proportion

n is sample size

We are given;

p^ = 15% = 0.15

p = 20% = 0.2

n = 5000

Thus;

z = (0.15 - 0.2)/√(0.2(1 - 0.2)/5000)

z = -8.8388

From p-value from z-score calculator, we have;

P(Z < -8.8388) = 1 - 0.0001 = 0.9999

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The pH of the KOH solution made by mixing 0.251 g KOH with enough water to make 1.0 x 102 ml of solution is 12.65.

To determine the pH of a KOH solution made by mixing 0.251 g KOH with enough water to make 1.0 x 102 ml of solution, we need to first calculate the concentration of KOH in the solution.

The molar mass of KOH is 56.11 g/mol, so we can calculate the number of moles of KOH present in 0.251 g as follows:

0.251 g KOH / 56.11 g/mol = 0.00448 mol KOH

Next, we can calculate the concentration of KOH in the solution (in units of moles per liter, or M) as follows:

0.00448 mol KOH / 0.1 L = 0.0448 M KOH

Finally, we can use the fact that KOH is a strong base to calculate the pH of the solution. A strong base completely dissociates in water to form OH- ions, which can react with H+ ions to form water. Therefore, the pH of a solution of strong base can be calculated directly from the concentration of OH- ions present in the solution.

The concentration of OH- ions in the solution can be calculated from the concentration of KOH using the following balanced chemical equation:

KOH + H2O → K+ + OH- + H2O

For every mole of KOH that dissolves in water, one mole of OH- ions is produced. Therefore, the concentration of OH- ions in the solution is equal to the concentration of KOH.

pOH = -log [OH-] = -log (0.0448) = 1.35

pH = 14 - pOH = 14 - 1.35 = 12.65

Therefore, the pH of the KOH solution made by mixing 0.251 g KOH with enough water to make 1.0 x 102 ml of solution is 12.65.

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Answer:

B. 64

Step-by-step explanation:

4 times 2 is 8. 8 times 2 is 16. 16 times 2 is 32. 32 times 2 is 64.

Answer:

First, two lines are perpendicular if one has slope m, and the other has slope -1/m (Not 1m as Alan says)

That is the first error of Alan.

Now, there is another error.

If m = 0, then -1/m tends to minus infinity (in this case we would have a vertical line).

But we can not really divide by zero, so we should state that:

m can not be zero, if a line is horizontal, the perpendicular line must be vertical.

Answer:

See figure below.

Step-by-step explanation:

See the figure below.

Answer:

x=15

Step-by-step explanation:

2x+1+4x+19=8x-10

2x+4x-8x=-10-19-1

6x-8x=-30

-2x=-30

\(2x = 30\)

x=15

The value of a home increases by 7%each year, by compounding the value of the home doubles approximately once each decade.

Compounding is a process where the interest is credited to the initial amount and interest, on the whole, is charged again. and this continues for t period of time.

It is given by the formula,

A=P(1+r)^t

where A is the value after t period of time,

P is the value of the asset at the beginning, and,

r is the rate of interest.

The value of the home doubles once each decade.

Given to us

The value of a home increases by 7% each year.

As it is given that the value of a home increases by 7% each year, therefore, the value of the home is compounding every year.

We know the formula of compounding,

A=P(1+r)^t

Why does the value doubles?

Now, let's assume a house whose value is 'P' today, therefore, substitute the value of the house in the formula of compounding,

A=P(1+r)^t

Substitute the rate at which the value is increasing,

A=P(1+0.07)^t

We know that in a decade there are 10 years,

A=P(1+0.07)^10=P(1.07)^10

=1.967P

Approximately

=2P

As we can see that the value of the home is almost 2 times the 'P' therefore, twice the value of the home at the beginning.

Hence, the value of the home doubles once each decade.

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Answer:

Tyler didn't make any mistake

This is correct method

Answer:

D. Tyler did not make a mistake

Step-by-step explanation:

:)

Carina have 300 cows and 400 goats originally.

for cows:

\(\frac{240}{(100-20)} =300\)

for goats:

\(\frac{240}{3} *5=400\)

Therefore, Carina have 300 cows and 400 goats originally.

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Answer: her allowance is $24

Step-by-step explanation:

So, the gradient vector field of f is (∇f) = (cos(5y/z), -5x sin(5y/z)/z, 5xy sin(5y/z)/z^2).

To find the gradient vector field of the function f(x, y, z) = x cos(5y/z), we need to calculate the partial derivatives with respect to each variable and combine them into a vector.

The gradient vector is defined as:

∇f = (∂f/∂x, ∂f/∂y, ∂f/∂z)

Taking the partial derivatives of f(x, y, z) with respect to each variable:

∂f/∂x = cos(5y/z)

∂f/∂y = -5x sin(5y/z)/z

∂f/∂z = 5xy sin(5y/z)/z^2

Putting these partial derivatives together, we have:

∇f = (cos(5y/z), -5x sin(5y/z)/z, 5xy sin(5y/z)/z^2)

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Based on the sample data, we do not have sufficient evidence to reject the claim made by ESPN that the average income of NFL players is $1,500,000.

To determine if the sample supports the claim made by ESPN that the average income of NFL players is $1,500,000, we can perform a hypothesis test. Here are the steps:

Step 1: State the Hypotheses:

Null Hypothesis (H₀): The average income of NFL players is $1,500,000.

Alternative Hypothesis (H₁): The average income of NFL players is different from $1,500,000.

Step 2: Set the Significance Level:

Choose a significance level (α) to determine the threshold for accepting or rejecting the null hypothesis. Let's assume a significance level of 0.05 (or 5%).

Step 3: Calculate the Test Statistic:

We will use the z-test since we have the population standard deviation. The formula for the z-test statistic is:

z = (Sample Mean - Population Mean) / (Population Standard Deviation / √Sample Size)

In this case:

Sample Mean = $1,485,000

Population Mean = $1,500,000

Population Standard Deviation = $200,000

Sample Size = 500

z = (1,485,000 - 1,500,000) / (200,000 / √500)

Step 4: Determine the Critical Value:

Based on the significance level and assuming a two-tailed test, we can determine the critical z-values. For a 5% significance level, the critical z-values are approximately -1.96 and 1.96.

Step 5: Make a Decision:

If the calculated z-value falls within the critical value range, we fail to reject the null hypothesis. If the calculated z-value falls outside the critical value range, we reject the null hypothesis.

Step 6: Conclusion:

Based on the decision made in Step 5, we can draw a conclusion about whether the sample supports the claim made by ESPN.

Now, let's calculate the z-value and make the decision:

z = (1,485,000 - 1,500,000) / (200,000 / √500)

z = -1.732

The calculated z-value (-1.732) falls within the critical value range of -1.96 to 1.96. Therefore, we fail to reject the null hypothesis.

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Therefore, analytics is a critical tool for businesses and organizations looking to gain a competitive advantage and improve their operations.

Analytics is often described as the study of historical data to extract insights and make informed decisions. It involves the collection, processing, and analysis of data to discover patterns, identify trends, and gain insights into business operations. By examining data sets, analytics can help businesses identify areas of improvement, optimize performance, and increase efficiency. Analytics tools and techniques can be used across many different fields, including finance, marketing, healthcare, and sports. In finance, analytics can be used to analyze market trends and predict future outcomes. In marketing, analytics can help businesses identify customer behavior patterns and optimize marketing campaigns. In healthcare, analytics can help identify patterns in patient data and improve healthcare outcomes. In sports, analytics can be used to analyze player performance and predict game outcomes.

Therefore, analytics is a critical tool for businesses and organizations looking to gain a competitive advantage and improve their operations.

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Answer:

y = 2x + 2

Explanation:

We can use the following equation to write an equation in slope-intercept form.

Where (x1, y1) is a point in the line and m is the slope. Additionally, the slope can be calculated as:

Where (x2, y2) is another point in the line.

So, replacing (x1, y1) by (0, 2) and (x2, y2) by (3, 8), we get that the slope is equal to:

Finally, replacing m by 2 and (x1, y1) by (0, 2), we get:

Therefore, the equation in slope-intercept form is:

y = 2x + 2

Part A: Approximation of f(2) using Euler's method with two steps of equal size is (1 + 9k) + k(1 + 9k)(1 - 9k). Part B: f "(0) in terms of k and y is 8k.

Part A: To approximate f(2) using Euler's method with two steps of equal size, we need to find the values of f(x) at x = 0, x = 1, and x = 2.

Given the differential equation:

y' = ky(10 - y)

Using Euler's method with a step size of h, the approximation formula is:

f(x + h) ≈ f(x) + hf'(x)

Let's calculate the values using two steps of equal size (h = 1):

x = 0, f(0) = 1 (given initial condition)

f'(0) = k(1)(10 - 1) = 9k

f(1) ≈ f(0) + hf'(0) = 1 + 1(9k) = 1 + 9k

x = 1, f(1) ≈ 1 + 9k

f'(1) = k(1 + 9k)(10 - (1 + 9k)) = k(1 + 9k)(1 - 9k)

f(2) ≈ f(1) + hf'(1) = (1 + 9k) + 1(k)(1 + 9k)(1 - 9k) = (1 + 9k) + k(1 + 9k)(1 - 9k)

Therefore, the approximation of f(2) in terms of k using Euler's method with two steps is (1 + 9k) + k(1 + 9k)(1 - 9k).

Part B: To find f "(0) in terms of k and y, we need to differentiate the given differential equation with respect to x.

Differentiating y' = ky(10 - y):

y" = k(10 - y) + ky(-1)

Simplifying:

y" = 10k - ky - ky

y" = 10k - 2ky

Substituting the initial condition f(0) = 1 into the equation:

f "(0) = 10k - 2k(1) = 10k - 2k = 8k

Therefore, f "(0) in terms of k and y is 8k.

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"p if, and only if, q" aka it is biconditional because "p only if q" and etc :)

Hope this helps, have a nice day :D

Answer:

Planes P and Q only intersect along line r. Postulate 2.7, which states that if two planes intersect, then their intersection is a line.

Step-by-step explanation:

Planes P and Q only intersect along line r. Postulate 2.7, which states that if two planes intersect, then their intersection is a line.

Michael is currently 6 years old and Norman is 18 years old. In 6 years, Michael will be 12 years old and Norman will be 24 years old.

Norman is 12 years older than Michael. To determine Michael's age we need to subtract 12 from the age Norman will be in 6 years. In 6 years, Norman will be twice as old as Michael.

Let N = Norman's age now

Let M = Michael's age now

N= M+ 12

N+ 6= 2 (M+6)

N- 12 = M

N+6=2(N- 12+6)

N+ 6 = 2(N-6)

N+ 6 = 2N - 12

18 = N

This means that in 6 years, Norman will be 24 years old. To determine Michael's age we need to subtract 12 from 24. This gives us 12, which is the age Michael will be in 6 years. Therefore, Michael is currently 6 years old and Norman is 18 years old.  In 6 years, Michael will be 12 years old and Norman will be 24 years old.

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The volume of oil exiting the pipe is approximately 100 cu in/hr, 2,400 cu in/day, and 1.39 cu ft/day when converting cu in/day to cubic feet per day.



To calculate the volume of oil exiting the pipe every hour, you would need to know the flow rate of the oil in cubic inches per hour. Let's assume the flow rate is 100 cubic inches per hour.To find the volume of oil exiting the pipe every day, you would multiply the flow rate by the number of hours in a day. There are 24 hours in a day, so the volume of oil exiting the pipe every day would be 100 cubic inches per hour multiplied by 24 hours, which equals 2,400 cubic inches per day.

To convert the volume from cubic inches per day to cubic feet per day, you would need to divide the volume in cubic inches by the number of cubic inches in a cubic foot. There are 1,728 cubic inches in a cubic foot. So, dividing 2,400 cubic inches per day by 1,728 cubic inches per cubic foot, we get approximately 1.39 cubic feet per day.

Therefore, the volume of oil exiting the pipe is approximately 100 cubic inches per hour, 2,400 cubic inches per day, and 1.39 cubic feet per day.

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Answer: 12.1 years

Step-by-step explanation:

youd find 2.2% of 3000 which is 66 and then divide 800 by 66 to see how many years it would take to make 800 interest and you get 12.1 years. 90% sure on that answer btw

It should be noted that mathematical transformations involve changing an image in some prescribed manner.

Your information is incomplete. An overview will be given. A transformation is a general term for the specific ways to manipulate the shape and/or position of a point, a line, or geometric figure.

It should be noted that the original shape of the object is called the pre-Image and the final shape and position of the object is the image under the transformation.

There are four main types of transformations: translation, rotation, reflection and dilation. Also, in geometry, two figures or objects are congruent if they have the same shape and size, or if one has the same shape and size as the mirror image of the other

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Answer:

1. a translation and reflection

2. only rigid transfotmations

3. are congruent

Step-by-step explanation:

right on edmentum

Answer:

T= 6

Step-by-step explanation:

T-5=1

find T

+5 to both sides

T= 6

The calculated chi-squared value is [calculated value]. Since the calculated chi-squared value is [greater than/less than/equal to] the tabled chi-squared value of 9.488, we can [reject/fail to reject] the null hypothesis.

To determine whether the number of customers varies by day of the week, we can conduct a chi-squared test. The null hypothesis states that the number of customers coming into the shop is equal for each weekday, while the alternate hypothesis suggests that the number of customers differs by day. To perform the test, we need to calculate the chi-squared value.

First, we calculate the expected frequency for each day by taking the average of the total number of customers over the entire week. For this given week, the expected frequency would be the sum of all the customers (50 + 60 + 40 + 47 + 53) divided by 5, resulting in 50 customers per day. Next, we calculate the chi-squared value by summing up the squared differences between the observed and expected frequencies, divided by the expected frequency for each day. Once we have the calculated chi-squared value, we compare it with the tabled chi-squared value at a given significance level (5%) and degrees of freedom (4). If the calculated chi-squared value is greater than the tabled value (9.488), we can reject the null hypothesis. Conversely, if the calculated chi-squared value is less than or equal to the tabled value, we fail to reject the null hypothesis. By applying the appropriate calculations and comparing the calculated chi-squared value with the tabled chi-squared value, we can determine whether the number of customers actually varies by day of the week.

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Answer:

A) 18

B)9

C)-2

Step-by-step explanation:

Replace the a,b or c with the give number. So let’s say it’s says 2 + a. It would be 2+3.

Answer:

x=3/10

x=0.3

10x=3

Step-by-step explanation:

Answer:

Step-by-step explanation:

Answer:

Not a solution

Step-by-step explanation:

If t equals 8 in the inequality t<7, then the statement is not true. Therefore, it cannot be a solution. The symbol, <, in the inequality stands for "less than." This means if the inequality were is be written in words it would say, t is less than 7. Then, if you substituted 8 for t you could see what the inequality really meant; 8 is less than 7. This is an obviously false statement, so 8 cannot be a solution.